Firsts

First UK-produced radio game show: The oldest show for which we have a listing is the write-in quiz What's Wrong with This? from 1925. The earliest we know of with actual on-air contestants is Inter Regional Spelling Competition, broadcast on the BBC Regional Service on 25 November 1937.

First TV game show: Spelling Bee, shown by the British Broadcasting Corporation (BBC) on 31st May 1938, transmitted live from Alexandra Palace.

First TV game show offering cash prizes: Take Your Pick, broadcast on 23rd September 1955 by Associated-Rediffusion.

Broadcasting records

Longest running

Longest-running game show (TV): This used to be an easy one to call, as Come Dancing enjoyed such a head start that even after it ended, it took a very long time for other long-runners to catch up. However, as that show didn't have a made-for-TV competition format for its first couple of years (it covered existing contests, but didn't stage its own), we can now declare it officially overtaken, by not one but two shows: A Question of Sport and University Challenge.

Which of those is the actual longest-running, depends on how you measure it. Counting only the periods when they ran as regular series, University Challenge (21/9/62 to 3/9/87 and 21/9/94 to present) beats A Question of Sport (5/1/70 to present), but if you count AQoS from its regional pilot (2/12/68) then it has the upper hand. Though if you consider the UC revival to have begun with the 1992 special, then University Challenge takes the lead again. It's a big can of worms, but two things we can say for certain are that AQoS has the longest continuous period in regular production, while UC has aired new episodes in the most different calendar years; 2016 was its fiftieth (while "only" the 48th for AQoS).

All-time longest-running game show (radio):Round Britain Quiz has run continuously since 1947.

Longest-running game show broadcast in UK (TV): Technically, it's A Song for Europe, which first aired in 1957, and annually between 1959 and 2010 (sometimes under different titles). The Eurovision Song Contest has been broadcast annually since 1956, but is not usually a UK production.

Most episodes produced: Countdown aired its 6000th episode on 5 September 2014, and is still going strong with around 250 new episodes each year.

Shortest running

All-time shortest-running game show (TV): Aside from intentional one-offs, ITV Play's The Debbie King Show started and ended on Monday 5th March 2007.

Hosts

Longest serving hosts

Longest tenure by time (TV): Counting only regular series, Magnus Magnusson's span as host of Mastermind lasted ten days short of 25 years, beating Bamber Gascoigne's tenure on University Challenge by eight days. However, if you count the 1987 International University Challenge specials which followed the end of the regular series, then Bamber's run is extended by nearly four months. You could extend it even further by including Bamber's appearances on the 1992 one-off, and 1998's Red Dwarf special, but then you'd also have to count Geoffrey Wheeler's technical 44-year span on Television Top of the Form, which beats all comers. Not far behind comes Richard Whiteley, who had been hosting Countdown for nearly 23 years at the time of his death in 2005 - in fact, if you include the show's regional precursor Calendar Countdown, he actually passed the 23-year mark. The longest-serving current host is Jeremy Paxman, who's been at the helm of University Challenge since 1994. The longest-serving female host is Sue Barker, who's been posing A Question of Sport since 1997. The previous record-holder was Cilla Black, who dished up over 17 years of Blind Date.

Longest tenure by time (radio): Nicholas Parsons has presented nearly every programme of Just a Minute since 1967. However, as Parsons very occasionally lets guest hosts take the chair, Humphrey Lyttelton is possibly the host with the longest unbroken spell as he spent nearly 36 years sitting on Samantha's left hand from 1972.

Longest tenure by on-air time (TV): With 30 or 45 minutes of exposure almost every weekday for 23 years, Countdown host Richard Whiteley is the out-and-out winner here. It is estimated that up to his death he was the second-most frequently seen face on British television, second only to the test card girl Carol Hersee.

Doubles and trebles: Some of the most prestigious quizzes do not carry huge prizes, so the following contestants are not necessarily the most successful financially, but have won multiple "prestige" shows:

Highest cash prize offered: The highest prize possible on Shafted was £2.5 million. This was an artificial cap as technically £102 million could have been won without it.

Highest cash prize won by a viewer: Karen Shand won £1 million by phoning into The Vault on 3rd August 2004.

Highest cash prize won on a BBC production: On 23 June 2007, Stephanie Bruce won £200,700 on People's Quiz. The previous record was held by Eleri Owen who won £100,000 on In It to Win It by answering 21 questions in a row. The BBC's 1 vs 100 offered £250,000 but nobody took home a six-figure sum. An investment of £250,000 has been the prize on The Apprentice since 2011, making it technically the richest game show on the BBC. Two investments of £250,000 have also been offered and accepted on Dragons' Den though both subsequently fell through. Although one suspects it didn't come out of the BBC's own budget, the £1m recording contract offered as part of the winner's package on Fame Academy is also worth a mention.

Daytime TV

Highest cash prize offered on daytime TV: Tenable, offers £125,000 per episode. Before it went out of production, Deal or No Deal had offered £250,000 every episode and between episodes 2,417 and 2,991 inclusive £500,000; technically For the Rest of Your Life nominally matched this, although in that instance it would have been near impossible to obtain and besides would probably have ended up cheaper than the stated cash value given the annuity.

Non-cash prizes

Highest non-cash prize offered: £2 million in total was awarded as venture capital to two winners £1 million each on 16 July 2000 in The E-millionaire Show.

Most valuable tangible prize offered: In terms of objects given as prizes, the house awarded on Love Thy Neighbour in 2011 is possibly the highest-value item ever given away, with a claimed value of £300,000. The house constructed and won on Building the Dream in 2004 had an estimated value at the time of £500,000+, though it later sold for a rather more modest £235,000. Nine years earlier, Raise the Roof offered £100,000+ houses as prizes.

Costs

Most expensive set: Undoubtedly The Crystal Maze set, which cost a few million pounds over its lifespan. Second place probably goes to Ice Warriors, which cost 1.5 million pounds. The most expensive set for a quiz belonged to The People Versus, which cost about half a million.

Ratings

Highest rated game show

This rather depends on who you ask and when you ask them. In 1992 Boxtree published 40 Years of British Television, which included as an appendix month-by-month top 20 TV listings charts.

The Generation Game was also the top-rating show under the pre-1977 ratings system (which counted households rather than individual viewers), 9.7 million households tuning in for a Christmas 1976 edition.

ITV's best rating for a game show came on 22nd December 1978 when an all-out strike at the BBC meant that 21.2 million viewers watched Sale of the Century.

This is all well and good, except that in 2005 Channel 4 broadcast a programme called Britain's Most Watched TV, for which the British Film Institute provided the lists (A top 20 for each of the 60s, 70s and 80s, and a top five for the 50s and 00s). Even though these lists drew on the same source material, they came out rather differently. It seems likely that the BFI disregarded high ratings that were attributable to a strike by "the other side", since otherwise there's a suspicious-looking hole in the autumn of 1979. Two other differences are pointed out by the BFI website: firstly, they multiplied "household" figures by 2.2 to produce an estimated audience in terms of individual viewers; and secondly the demands of the production company (Objective North) meant that "in some cases only the highest-rated example of similar programmes have been included to avoid repetition". This may account for the non-appearance of The Generation Game in their list. So according to the BFI, the top-rating game shows are:

It should be mentioned that for the 2000s, the Tonight with Trevor MacDonald special about the Ingram affair got an audience of 16.10m.

The BFI listing for the 1950s only includes shows from the last three months of 1959, presumably because figures for BBC shows are not available until then. Take Your Pick is the top-rating show for the period, with a peak audience of 13.16m.

The full top 20 lists can be found on the BFI website (archive.org link).

Looking beyond the end of the BFI data in 2004, the final of Britain's Got Talent on 30 May 2009 ended up as the top rated show of the decade, with final audience figures of 18.294m putting it comfortably ahead of any other game show in the 00s.

The top rated show of the 2010's (so far) is the final of The X Factor on 12 December 2010, with audience figures of 17.709m (including viewers watching on ITV1 HD).

In 2016, the Press Association issued its own "most watched" list to tie in with the 80th anniversary of regular 405-line TV broadcasts. Somehow, theirs differed as well, with the only game show in their top 20 being yet another different episode of Sale of the Century, from 19 November 1977, credited with an audience of 20.6m.